Trailer hitch assembly

Abstract

Towing apparatus for connecting a trailer with a towing vehicle. The towing apparatus is adapted to bear part of the weight of the trailer, thus lessening the load on the towing vehicle. This is accomplished by providing a wheel assembly on the towing apparatus which is operatively connected to an adjustable main spring which supports most of the weight of the trailer which would normally bear on the hitch of the towing vehicle. Unlike conventional towing systems, wherein the trailer tongue is rigidly attached to the trailer, the towing apparatus of the present invention employs a pivotally-mounted trailer tongue which is maintained in a horizontal position by an adjustable secondary spring or springs. The use of main and secondary springs presents a relatively constant load to the trailer hitch, even when the trailer is being towed across rough or uneven surfaces.

What is claimed is:  
     
       1. Towing apparatus for connecting a trailer to a towing vehicle comprising: 
       a) a trailer frame having a backwardly-extending rear frame portion for mounting the trailer frame to the trailer and a frontwardly-extending frame portion which is adapted to extend in the direction of the towing vehicle, said frontwardly-extending frame portion comprising:  
       i) a main frame assembly, and  
       ii) a secondary-spring-supporting frame member, said main frame assembly and said secondary-spring-supporting member integral with said trailer frame;  
       b) a trailer tongue, having a trailer hitch coupling at one end for attaching the towing apparatus to the towing vehicle, and a pivotal connector at the other end for pivotally mounting the trailer tongue to the trailer frame;  
       c) a wheel assembly having a top end and a bottom end, the top end comprising a wheel spindle, and the bottom end connected to a wheel;  
       d) a bottom link assembly pivotally mounted to the trailer frame, a front end of the bottom link assembly operatively connected to said wheel assembly;  
       e) an adjustable main spring depending from said main frame assembly and operatively connected to said bottom link assembly for biasing the bottom link assembly in a downward direction; and  
       f) an adjustable secondary spring having a top end mounted to said secondary-spring-supporting frame member, and a bottom end of said secondary spring connected to the trailer tongue for urging said trailer tongue in a downward direction.  
     
     
       2. Towing apparatus in accordance with claim  1  wherein connection of said trailer tongue to the trailer frame comprises a pin in a bushing connection. 
     
     
       3. Towing apparatus in accordance with claim  1  wherein said frontwardly-extending frame portion includes a pair of spaced-apart tongue-supporting frame members, and said trailer tongue comprises a wishbone-shaped frame having first and second tongue frame elements, each frame element having a pivotal connector therein, and mounting apparatus for pivotally attaching said frame elements to said tongue-supporting frame members. 
     
     
       4. Towing apparatus in accordance with claim  3  wherein the frontwardly-extending frame portion includes a pair of spaced secondary-spring-supporting frame members, first and second springs mounted, respectively, to said secondary-spring-supporting frame members, a bottom portion of said first spring bearing against said first tongue frame element, and a bottom end of said second spring bearing against said second tongue frame element. 
     
     
       5. Towing apparatus in accordance with claim  1  wherein said wheel assembly is retractable. 
     
     
       6. Towing apparatus in accordance with claim  5 , further including a carrier link assembly having a front portion and a rear portion, the front portion pivotally mounted to an idler frame assembly, and the rear portion attached to a carrier bar. 
     
     
       7. Towing apparatus in accordance with claim  6  wherein the carrier bar comprises a spindle sleeve. 
     
     
       8. Towing apparatus in accordance with claim  7  wherein said wheel spindle is journaled in the spindle sleeve. 
     
     
       9. Towing apparatus in accordance with claim  6  wherein the wheel spindle comprises a sleeve. 
     
     
       10. Towing apparatus in accordance with claim  9  wherein said carrier bar is journaled in the sleeve. 
     
     
       11. Towing apparatus in accordance with claim  1 , further including a shock absorber mounted between said main frame assembly and said bottom link assembly. 
     
     
       12. Towing apparatus in accordance with claim  1  wherein said adjustable main spring and said adjustable secondary spring comprise air springs. 
     
     
       13. Towing apparatus for connecting a trailer to a towing vehicle comprising: 
       a) a trailer frame having a backwardly-extending rear frame portion for mounting the trailer frame to the trailer and a frontwardly-extending frame portion which is adapted to extend in the direction of the towing vehicle, said frontwardly-extending frame portion comprising:  
       i) a main frame assembly, and  
       ii) a secondary-spring-supporting frame member, said main frame assembly and said secondary-spring-supporting member integral with said trailer frame;  
       b) a trailer tongue, having a trailer hitch coupling at one end for attaching the towing apparatus to the towing vehicle, and a pivotal connector at the other end for pivotally mounting the trailer tongue to the trailer frame;  
       c) a wheel assembly having a top end and a bottom end, the top end comprising a wheel spindle, and the bottom end connected to a wheel;  
       d) a bottom link assembly pivotally mounted to the trailer frame, a front end of the bottom link assembly operatively connected to said retractable wheel assembly, and a lifting mechanism adapted to contact the bottom link assembly for raising and lowering said wheel assembly;  
       e) an adjustable main spring depending from said main frame assembly and operatively connected to said bottom link assembly for biasing the bottom link assembly in a downward direction; and  
       f) an adjustable secondary spring having a top end mounted to said secondary-spring-supporting frame member, and a bottom end of said secondary spring connected to the trailer tongue for urging said trailer tongue in a downward direction.  
     
     
       14. Towing apparatus for connecting a trailer to a towing vehicle comprising: 
       a) a trailer frame having a backwardly-extending rear frame portion for mounting the trailer frame to the trailer and a frontwardly-extending frame portion which is adapted to extend in the direction of the towing vehicle, said frontwardly-extending frame portion comprising:  
       i) a main frame assembly, and  
       ii) a secondary-spring-supporting frame member, said main frame assembly and said secondary-spring-supporting member integral with said trailer frame;  
       b) a wishbone-shaped trailer tongue having spaced-apart first and second tongue legs pivotally mounted to the trailer frame, having a trailer hitch coupling at one tongue end for attaching the towing apparatus to the towing vehicle, and a pivotal connector at the other end for pivotally mounting the trailer tongue to the trailer frame;  
       c) a wheel assembly having a top end and a bottom end, the top end comprising a wheel spindle, and the bottom end connected to a wheel;  
       d) a bottom link assembly pivotally mounted to the trailer frame, a front end of the bottom link assembly operatively connected to said retractable wheel assembly, and a lifting mechanism adapted to contact the bottom link assembly for raising and lowering said wheel assembly;  
       e) an adjustable main spring depending from said main frame assembly and operatively connected to said bottom link assembly for biasing the bottom link assembly in a downward direction; and  
       f) an adjustable secondary spring having a top end mounted to said secondary-spring-supporting frame member, and a bottom end of said secondary spring connected to the trailer tongue for urging said trailer tongue in a downward direction.  
     
     
       15. Towing apparatus for connecting a trailer to a towing vehicle comprising: 
       a) a trailer frame having a backwardly-extending rear frame portion for mounting the trailer frame to the trailer and a frontwardly-extending frame portion which is adapted to extend in the direction of the towing vehicle, said frontwardly-extending frame portion comprising:  
       i) a main frame assembly, and  
       ii) a secondary-spring-supporting frame member, said main frame assembly and said secondary-spring-supporting member integral with said trailer frame;  
       b) a wishbone-shaped trailer tongue having first and second tongue legs each pivotally connected to the trailer frame, and a trailer hitch coupling for attaching the towing apparatus to the towing vehicle;  
       c) a wheel assembly having a top end and a bottom end, the top end comprising a wheel spindle, and the bottom end connected to a wheel;  
       d) a bottom link assembly pivotally mounted to the trailer frame, a front end of the bottom link assembly operatively connected to said retractable wheel assembly, and a lifting mechanism adapted to contact the bottom link assembly for raising and lowering said wheel assembly;  
       e) an adjustable main spring depending from said main frame assembly and operatively connected to said bottom link assembly for biasing the bottom link assembly in a downward direction; and  
       f) a pair of adjustable secondary springs, each secondary spring having a top end mounted to said secondary-spring-supporting frame member and a bottom end, the bottom end of one said secondary spring operatively connected to the first tongue leg and the bottom end of the other secondary spring operatively connected to the second tongue for urging said trailer tongue in a downward direction.  
     
     
       16. In a trailer having load-dampening apparatus for controlling the load of the trailer on a trailer hitch, the improvement comprising: 
       a) a wishbone-shaped trailer tongue having spaced-apart first and second tongue legs, each leg pivotally mounted to said trailer, and a front end of the trailer tongue having a coupling for attachment to said trailer hitch;  
       b) a centrally-disposed main frame assembly trailer frame extending frontwardly from said trailer;  
       c) a pair of secondary-spring-supporting frame members extending frontwardly from said trailer, one on each side of said main frame member, the end of each frame member located above a trailer tongue leg;  
       d) first and second secondary springs mount at the end of each frame member, an end of said first spring in operative contact with said first tongue leg, and an end of said second spring in operative contact with said second tongue leg;  
       e) a retractable wheel assembly having a top end and a bottom end, the top end comprising a wheel spindle, and the bottom end connected to a wheel;  
       f) a bottom link assembly pivotally mounted to the trailer frame, a front end of the bottom link assembly operatively connected to said retractable wheel assembly, and a lifting mechanism adapted to contact the bottom link assembly for raising and lowering said wheel assembly;  
       g) an adjustable main spring depending from said main frame assembly and operatively connected to said bottom link assembly for biasing the bottom link assembly in a downward direction; and  
       h) an adjustable secondary spring having a top end mounted to said secondary-spring-supporting frame member, and a bottom end of said secondary spring connected to the trailer tongue for urging said trailer tongue in a downward direction.